Spice3f5

BSIM2 transfer characteristics

The same five-transistor test as the BSIM1 example with a BSIM2 model, swept by a slow transient ramp.

The BSIM1 test circuit with a BSIM2 (LEVEL=5) model. Here the gate voltage is swept by a transient analysis: VGS ramps from 0 to 5V in 5 seconds, so time in the plot is the gate voltage in volts, and the ramp is slow enough for the result to match a DC sweep. .options acct prints the analysis statistics at the end of the run.

020µ40µ60µ012345time (s)i(v1)i(v2)i(v3)i(v4)i(v5)
Drain current as the gate ramps from 0 to 5V, VBS = 0 to -4V
  • i(v1)
  • i(v2)
  • i(v3)
  • i(v4)
  • i(v5)

Output

              Test of MOS BSIM2 implementation; DC transfer curve
                  Transient Analysis Tue Sep 29 09:06:41  2026
--------------------------------------------------------------------------------
Index	time         i(V1)        i(V2)        i(V3)        
--------------------------------------------------------------------------------
0	0.000000e+00	1.259693e-13	2.302983e-12	4.496301e-12	
1	1.000000e-04	1.210123e-13	2.297983e-12	4.491301e-12	
2	2.000000e-04	1.210556e-13	2.297983e-12	4.491301e-12	
3	4.000000e-04	1.211423e-13	2.297983e-12	4.491301e-12	
4	8.000000e-04	1.213171e-13	2.297983e-12	4.491301e-12	
5	1.600000e-03	1.216724e-13	2.297983e-12	4.491301e-12	
6	3.200000e-03	1.224058e-13	2.297983e-12	4.491301e-12	
7	6.400000e-03	1.239690e-13	2.297983e-12	4.491301e-12	
8	1.280000e-02	1.275205e-13	2.297983e-12	4.491301e-12	
9	2.280000e-02	1.344223e-13	2.297983e-12	4.491301e-12	
10	3.280000e-02	1.434082e-13	2.297983e-12	4.491301e-12	
11	4.280000e-02	1.551078e-13	2.297983e-12	4.491301e-12	
12	5.280000e-02	1.703403e-13	2.297983e-12	4.491301e-12	
13	6.280000e-02	1.901728e-13	2.297983e-12	4.491301e-12	
14	7.280000e-02	2.159941e-13	2.297983e-12	4.491301e-12	
15	8.280000e-02	2.496130e-13	2.297983e-12	4.491301e-12	
16	9.280000e-02	2.933838e-13	2.297983e-12	4.491301e-12	
17	1.028000e-01	3.503724e-13	2.297983e-12	4.491301e-12	
18	1.128000e-01	4.245699e-13	2.297983e-12	4.491301e-12	
19	1.228000e-01	5.211730e-13	2.297984e-12	4.491301e-12	
20	1.328000e-01	6.469475e-13	2.297984e-12	4.491301e-12	
21	1.428000e-01	8.107022e-13	2.297984e-12	4.491301e-12	
22	1.528000e-01	1.023906e-12	2.297984e-12	4.491301e-12	
23	1.628000e-01	1.301490e-12	2.297984e-12	4.491301e-12	
24	1.728000e-01	1.662896e-12	2.297984e-12	4.491301e-12	
25	1.828000e-01	2.133435e-12	2.297984e-12	4.491301e-12	
26	1.928000e-01	2.746059e-12	2.297985e-12	4.491301e-12	
27	2.028000e-01	3.543676e-12	2.297985e-12	4.491301e-12	
28	2.128000e-01	4.582143e-12	2.297986e-12	4.491301e-12	
29	2.228000e-01	5.934189e-12	2.297987e-12	4.491301e-12	
30	2.328000e-01	7.694502e-12	2.297988e-12	4.491301e-12	
31	2.428000e-01	9.986360e-12	2.297990e-12	4.491301e-12	
32	2.528000e-01	1.297027e-11	2.297992e-12	4.491301e-12	
33	2.628000e-01	1.685520e-11	2.297995e-12	4.491301e-12	
34	2.728000e-01	2.191321e-11	2.297999e-12	4.491301e-12	
35	2.828000e-01	2.849853e-11	2.298005e-12	4.491301e-12	
36	2.928000e-01	3.707233e-11	2.298012e-12	4.491301e-12	
37	3.028000e-01	4.823504e-11	2.298023e-12	4.491301e-12	
38	3.128000e-01	6.276838e-11	2.298037e-12	4.491301e-12	
39	3.228000e-01	8.169012e-11	2.298057e-12	4.491301e-12	
40	3.328000e-01	1.063253e-10	2.298084e-12	4.491301e-12	
41	3.428000e-01	1.383992e-10	2.298120e-12	4.491301e-12	
42	3.528000e-01	1.801578e-10	2.298169e-12	4.491301e-12	
43	3.628000e-01	2.345254e-10	2.298237e-12	4.491301e-12	
44	3.728000e-01	3.053093e-10	2.298328e-12	4.491301e-12	
45	3.828000e-01	3.974663e-10	2.298453e-12	4.491301e-12	
46	3.928000e-01	5.174499e-10	2.298623e-12	4.491301e-12	
47	4.028000e-01	6.736621e-10	2.298855e-12	4.491301e-12	
48	4.128000e-01	8.770419e-10	2.299171e-12	4.491301e-12	
49	4.228000e-01	1.141831e-09	2.299601e-12	4.491301e-12	
50	4.328000e-01	1.486572e-09	2.300187e-12	4.491301e-12	
51	4.428000e-01	1.935405e-09	2.300985e-12	4.491301e-12	
52	4.528000e-01	2.519760e-09	2.302071e-12	4.491301e-12	
53	4.628000e-01	3.280555e-09	2.303552e-12	4.491301e-12	
54	4.728000e-01	4.271065e-09	2.305568e-12	4.491301e-12	
55	4.828000e-01	5.560650e-09	2.308315e-12	4.491301e-12	
56	4.928000e-01	7.239610e-09	2.312056e-12	4.491301e-12	
57	5.028000e-01	9.425511e-09	2.317153e-12	4.491301e-12	
58	5.128000e-01	1.227142e-08	2.324094e-12	4.491301e-12	
59	5.228000e-01	1.597660e-08	2.333550e-12	4.491301e-12	
60	5.328000e-01	2.080051e-08	2.346429e-12	4.491301e-12	
61	5.428000e-01	2.708091e-08	2.363973e-12	4.491302e-12	
62	5.528000e-01	3.525744e-08	2.387869e-12	4.491302e-12	
63	5.628000e-01	4.590218e-08	2.420418e-12	4.491302e-12	
64	5.728000e-01	5.975865e-08	2.464755e-12	4.491303e-12	
65	5.828000e-01	7.779122e-08	2.525146e-12	4.491304e-12	
66	5.928000e-01	1.012461e-07	2.607406e-12	4.491305e-12	
67	6.028000e-01	1.310513e-07	2.719455e-12	4.491306e-12	
68	6.128000e-01	1.685279e-07	2.872077e-12	4.491308e-12	
69	6.228000e-01	2.138138e-07	3.079966e-12	4.491311e-12	
70	6.328000e-01	2.678470e-07	3.363135e-12	4.491315e-12	
71	6.428000e-01	3.315731e-07	3.748843e-12	4.491320e-12	
72	6.528000e-01	4.059471e-07	4.274220e-12	4.491328e-12	
73	6.628000e-01	4.919382e-07	4.989843e-12	4.491339e-12	
74	6.728000e-01	5.905402e-07	5.964599e-12	4.491353e-12	
... (963 more lines)

The circuit: examples/bsim2tst.cir

Test of MOS BSIM2 implementation; DC transfer curve
****************************************************************** 
MN1 13 2 0 4 NMOS L=10U W=50.0U AD=100P AS=100P PD=40U PS=40U   
MN2 23 2 0 5 NMOS L=10U W=50.0U AD=100P AS=100P PD=40U PS=40U   
MN3 33 2 0 6 NMOS L=10U W=50.0U AD=100P AS=100P PD=40U PS=40U   
MN4 43 2 0 7 NMOS L=10U W=50.0U AD=100P AS=100P PD=40U PS=40U   
MN5 53 2 0 8 NMOS L=10U W=50.0U AD=100P AS=100P PD=40U PS=40U   
VDS 3 0 0.05    
V1 3 13 0       
V2 3 23 0       
V3 3 33 0       
V4 3 43 0       
V5 3 53 0       
VBS1 4 0 0      
VBS2 5 0 -1
VBS3 6 0 -2     
VBS4 7 0 -3
VBS5 8 0 -4     
*************************************************************** 
* for DC analysis
*dc VGS 0 5 0.01
* for tran analysis
VGS  2  0  DC 0 PWL(0 0 5 5)
.options ACCT
.control
*options LIMPTS=5000 ACCT       
*print i(V1) i(V2) i(V3) i(V4) i(V5) 
*plot  i(V1) i(V2) i(V3) i(V4) i(V5) 
*tran 0 5 0.01
tran 0.01 5
print i(V1) i(V2) i(V3) i(V4) i(V5)
plot i(V1) i(V2) i(V3) i(V4) i(V5)
.endc
***** MODEL PARAMETERS TEMP2 ********************       
* This file contains the BSIM2 process file parameters as they should
* be input to the .model card of spice3c1.
.model nmos nmos level=5 
+ vfb =  -0.7919 lvfb =  -0.0266 wvfb =   0.0000 
+ phi =   0.8039  lphi =   0.0042  wphi =   0.0000 
+ k1  =   0.7286  lk1  =   0.0309  wk1  =   0.0000 
+ k2  =  -0.0506  lk2  =   0.0786  wk2  =   0.0000 
+ mu0 = 453.2926  dl =   0.1553  dw =   0.0000 
+ mu0b =  -5.4925  lmu0b =  -1.9192  wmu0b =   0.0000 
+ mus0 = 781.7117  lmus0 =  25.2769  wmus0 =   0.0000 
+ musb =  25.5724  lmusb = -10.0060  wmusb =   0.0000 
+ mu20 =   0.9390  lmu20 =  -0.0840  wmu20 =   0.0000 
+ mu2b =   0.0753  lmu2b =  -0.0148  wmu2b =   0.0000 
+ mu2g =   0.1804  lmu2g =   0.0181  wmu2g =   0.0000 
+ mu30 =  44.9689  lmu30 =  -0.0933  wmu30 =   0.0000 
+ mu3b =   0.5871  lmu3b =   1.0793  wmu3b =   0.0000 
+ mu3g = -11.6723  lmu3g =   0.6804  wmu3g =   0.0000 
+ mu40 =   0.2682  lmu40 =   2.3969  wmu40 =   0.0000 
+ mu4b =  -0.3179  lmu4b =   0.1264  wmu4b =   0.0000 
+ mu4g =  -0.2654  lmu4g =  -0.5702  wmu4g =   0.0000 
+ ua0 =   0.0441  lua0 =   0.2283  wua0 =   0.0000 
+ uab =  -0.0045  luab =  -0.0105  wuab =   0.0000 
+ ub0 =   0.0125  lub0 =  -0.0051  wub0 =   0.0000 
+ ubb =  -0.0015  lubb =   0.0010  wubb =   0.0000 
+ u10 =   0.1262  lu10 =   0.5563  wu10 =   0.0000 
+ u1d =  -0.2967  lu1d =  -0.0062  wu1d =   0.0000 
+ u1b =   0.0960  lu1b =  -0.0345  wu1b =   0.0000 
+ eta0 =  -0.0373  leta0 =   0.0271  weta0 =   0.0000 
+ etab =   0.0004  letab =  -0.0041  wetab =   0.0000 
+ n0 =   0.8032  ln0 =   0.1734  wn0 =   0.0000 
+ nd =   0.0105  lnd =  -0.0091  wnd =   0.0000 
+ nb =   0.5978  lnb =  -0.1638  wnb =   0.0000 
+ vof0 =   1.4977  lvof0 =  -0.1766  wvof0 =   0.0000 
+ vofd =   0.1795  lvofd =  -0.1247  wvofd =   0.0000 
+ vofb =   0.8368  lvofb =  -0.3432  wvofb =   0.0000 
+ ai0 =  32.0150  lai0 =   8.2816  wai0 =   0.0000 
+ aib = -19.5396  laib =   4.9347  waib =   0.0000 
+ bi0 =  37.6044  lbi0 =  -1.8713  wbi0 =   0.0000 
+ bib =  -2.5109  lbib =   0.7903  wbib =   0.0000 
+ vghigh =   0.2342  lvghigh =  -0.0007  wvghigh =   0.0000 
+ vglow =  -0.1023  lvglow =   0.0038  wvglow =   0.0000 
+ tox = 0.0150 temp = 27 vdd = 5.0 vgg = 5.0 vbb =  -3.0 
+ cgdo = 1.0e-10 cgso = 1.0e-10 cgbo = 2.5e-11 
+ xpart = 0  
+ rsh = 0 cj = 0.0002 cjsw = 1.0e-10 
+ js = 5e-5 pb = 0.7 pbsw = 0.8 
+ mj = 0.5 mjsw = 0.33 wdf = 0 
+ dell = 0 
*****                                        *****      
.END

Run it with spice bsim2tst.cir, or open it with File › Load netlist in the Qt window. The plots and output above were made by util/mkexamples.py, which runs the deck in batch mode. All examples